As communications standards and signal frequency bands currently supported by a terminal are increasing, the terminal becomes more easily exposed to a problem that signals of different communications standards that are received and transmitted by the terminal coexist and interfere with each other. By using a wireless local area network (e.g., Wireless Fidelity (Wi-Fi)) and a Long Term Evolution (LTE) system as an example, because application frequency bands of the LTE system are various, where a quantity of frequency bands that are relatively close to a frequency band of Wi-Fi is relatively large, a currently common typical scenario of coexistence of signals of different communications standards is that a Wi-Fi signal coexists with an LTE system signal.
FIG. 1 is a schematic diagram of a scenario in which a Wi-Fi signal coexists with an LTE system signal. A mobile wireless local area network (Mobile Wi-Fi) terminal shown in FIG. 1 may be handed over between a Worldwide Interoperability for Microwave Access (WiMAX) system, an LTE system, and 2.4G Wi-Fi so as to provide data experience of wide coverage and high performance for a user on a downlink local area network (LAN) side. More specifically, an uplink wide area network (WAN) side of the Mobile Wi-Fi terminal may be a WiMAX system, an LTE system, or Wi-Fi, such that in an uplink direction, the Mobile Wi-Fi terminal may be connected to the Internet using the WiMAX system, the LTE system, the Wi-Fi, or the like. However, in a downlink direction, universal serial bus (USB) and Wi-Fi access may be provided, such that a device (for example, a mobile phone or a portable computer) that has a function of a Wi-Fi client (that is, Wi-Fi station (STA)) or a function of a USB interface may be connected to the Mobile Wi-Fi terminal using a Wi-Fi client installed on the device, so as to further implement indirect access to the Internet using the Mobile Wi-Fi terminal.
Currently, after entering an area covered by Wi-Fi, the Mobile Wi-Fi terminal can be automatically switched to accessing the Wi-Fi using a Wi-Fi hotspot (for example, a wireless access hotspot (Access Point (AP)), and access the Internet by means of Wi-Fi. However, after the Mobile Wi-Fi terminal leaves the area covered by the Wi-Fi, when there is no Wi-Fi hotspot nearby, the Mobile Wi-Fi terminal is switched again to accessing the Internet using the WiMAX system or the LTE system. By using this technology referred to as an offloading technology, coordination of multiple network resources in a unified manner may be implemented. For example, when the WiMAX system and the LTE system are congested, the technology may be used to implement offloading of some users to Wi-Fi.
When the foregoing offloading technology is implemented in an actual application, some channels of 2.4G Wi-Fi generate interference to a WiMAX system (or LTE system) channel; therefore, when the Mobile Wi-Fi terminal is handed over from the 2.4G Wi-Fi to the WiMAX (or LTE) system, because a 2.4G Wi-Fi signal transmitted by the Mobile Wi-Fi terminal interferes with a WiMAX (or LTE) system signal, a handover failure may be caused.
In addition, in the prior art, there is still a problem that a Wi-Fi channel on the downlink LAN side of the Mobile Wi-Fi terminal interferes with a WiMAX (or LTE) system channel on the uplink WAN side of the Mobile Wi-Fi terminal.